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2020, Vol. 31, No. 1

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  • Kirje
    Eesti erosioonist häiritud muldkatted: muldade nomenklatuur ja uurimise ajalugu
    (Estonian Academic Agricultural Society, 2020) Kõlli, Raimo; Tõnutare, Tõnu; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Mullateaduse õppetool
    The work, dedicated to the eroded soil i.e. the year 2020 soil of Estonia, consists of two-part. In Part I the general overview (a) the regularities of erosion processes and their forming conditions in the soil cover, and (b) the agro-ecological properties and nomenclature of formed erosion-affected soils (EAS), are treated. Totally in the Estonian soil classification (ESC) 11 eroded and 3 deluvial (colluvial) soil species have been determined. For the main criteria of eroded soils' determination is (a) the intensity or stage of erosion, and (b) the calcareousness of soil cover, but deluvial soils (a) the soils' water regime and (b) the thickness of formed deluvial humus horizon. In this part also the determination criteria of erosion-prone soils and the agronomic quality of EAS are analysed. In Part II the historic overview about scientific researches dedicated to the study of influenced by erosion soils during the last century in Estonia. In this overview, the main thematic issue and the role of leading scientists on researches of most actual problems are presented. The most important themes during this period were: (a) the elaboration suitable for local conditions EAS classification and methods for their field researches; (b) the distribution of EAS in Estonia; (c) the studies upon forming, composition and status of EAS-s; (d) forming databases on essential properties of EAS-s and derived from this the rules of their ecologically sustainable use, and finally (e) the international aspects of Estonian EAS presentation and local researches.
  • Kirje
    Mini-review: The role of crop rotation, intercropping, sowing dates and increased crop density towards a sustainable crop and weed management in arable crops
    (Estonian Academic Agricultural Society, 2020) Kanatas, Panagiotis
    The extended and in many cases unjustified use of herbicides has resulted in herbicide resistance development and serious environmental concerns. Therefore, the need for implementation and wider adoption of several agronomic and cultural practices is imperative. Ecologically-based crop management practices like crop rotation, intercropping, delay of sowing date and increased crop density can be also the basis for effective and sustainable weed management. In the present review, several cases are presented and the key points of each method are discussed. Special attention is given to the fact that the efficacy of each practice is depended on the specific soil and climatic conditions along with the field history of each site and crop. Alternative methods of weed management should be further studied and optimized to include them in both organic and conventional production systems and ensure the sustainability of agroecosystems.
  • Kirje
    Short communication: The improvement of the growth of tomato transplants by bokashi tea
    (Estonian Academic Agricultural Society, 2020) Olle, Margit
    Effective microorganisms' bokashi fermentation is proposed to upcycle food waste to novel feed supplements, and to (partially) replace traditional composting of food waste (and secondary residues from industrial processes) to facilitate both plant production and soil quality as well as to reduce greenhouse gas emissions. The purpose was to assess the influence of bokashi tea treatment on the growth of tomato transplants. There were two treatments: one with bokashi tea and second without bokashi tea (control). Tomato transplants treated with bokashi tea tended to be higher than those in control; while the results were not significantly different. The number of leaves of tomato transplants treated with bokashi tea was not significantly different. The stem diameter of tomato transplants was 13% greater (P = 0.04) in bokashi tea treated plants than in control. Conclusion: Bokashi tea improves the growth of tomato transplants by increasing stem diameter and is allowing for plants to take up more nutrients.
  • Kirje
    The aromatic plant Melissa officinalis and effects of its aqueous extracts on summer annual and invasive weed species
    (Estonian Academic Agricultural Society, 2020) Kanatas, Panagiotis
    The effects of aqueous extracts of the aromatic plant Melissa officinalis were studied on the seed germination and early seedlings growth of ten summer annual species in Petri dish bioassays and pot experiments. The in vitro experiments on the aqueous extracts from M. officinalis on seed germination shows that the extracts of 5 and 10% were the most active inhibitors for all the studied weed species. Seed germination reduction by the aqueous extracts was up to 54% of the untreated seed lot for each species. On the contrary, the concentration of 1% resulted in germination reduction ranging from 1 to 11%, while in some of the weed species (P. minor, S. nigrum, P. angulata and C. albida) the effect was rather stimulatory. This finding is in full agreement with “novel weapons hypothesis” and supports that native plants compared with invasive (like C. albida and P. angulata) are affected more due to the absence of tolerance or resistance to the allelochemicals. The allelopathy RI of aqueous extracts of lemon balm was negative in most cases, while in the case of 10% concentration, emergence was reduced by 58, 54, 48, 46 and 43% for X. strumarium, C. album, S. faberi, C. canadensis and C. bonariensis, respectively. The allelopathic activity of M. officinalis could be exploited in future studies, to identify and isolate the allelochemicals, as models for future herbicides for integrated weed management.
  • Kirje
    A theoretical and experimental study of the traction properties of agricultural gantry systems
    (Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Olt, Jüri; Kuvachov, Volodymyr; Smolinsky, Stanislav; Estonian University of Life Sciences. Institute of Technology
    The movement conditions experienced by an agricultural gantry system along the solid and level ground surface of permanent artificial tracks must make it possible to generate most of its maximum tractive force. Concurrently, the adhesive ability of the agricultural gantry system on the ground surface of such permanent artificial tracks must be sufficient to generate nominal drawbar pull when working at a certain level of slip. This means that there exists the need to seek out the following compromise: the maximum slippage experienced by the wheeled chassis of an agricultural gantry system must be such that, in a situation in which the level of adhesion with the surface of permanent artificial tracks is suitable, it will be able to generate the maximum possible tractive force. The effect of the parameters that involve an agricultural gantry system's wheels – and the physical and mechanical properties of the ground surface along which they move – on potential slippage has not yet been sufficiently studied. This effect cannot be taken into consideration without taking into account the dynamics of any rolling resistance being offered by the agricultural gantry system's chassis. The purpose of this particular study is to research the traction properties of an agricultural gantry system's wheeled chassis in terms of its movement along compacted and level ground upon which have been mounted permanent artificial tracks. The research determines that the wheels of such an agricultural gantry system that are rolling along permanent artificial tracks suffer less slippage and therefore generate a higher level of tractive force. As a result, the agricultural gantry system loses less of its speed of movement and, therefore, uses less energy in that movement. When an agricultural gantry system moves across an agricultural field that has been prepared for sowing, the research also determines the maximum tractive force that its wheels can develop when the adhesion coefficient is set at a figure that is between 0.22–0.24. Once such movement begins along permanent artificial tracks, this coefficient decreases to between 0.15–0.17. An agricultural gantry system's wheels are able to generate a higher level of tractive force when moving along on permanent artificial tracks. This figure is at least 30% higher when its movement has to be considered across an agricultural field that has been prepared for sowing.
  • Kirje
    Review: Managing weed populations through alteration of the cropping pattern
    (Estonian Academic Agricultural Society, 2020) Pacanoski, Zvonko; Mehmeti, Arben
    Alteration of the cropping pattern, such as manipulation of sowing date, increasing crop sowing rate, alteration in population density and row spacing, the use of cultivars that are more competitive and proper fertilization, particularly nitrogen application, have been the focus of many research studies. These studies aimed for the goal of boosting the crop's capacity to provide domination over weeds and surviving competitive stress. Modifications in sowing date might have tremendously influence on plants growth, but also have a prominent influence on weed infestation, crop development and yield. Changes in sowing dates are important to prevent the durations of considerable weed risks and consequently raise crop yield. High sowing rates increase the capacity of crops to overcome weeds and preserve yield loss under moderate weediness of the crop. Further, increased crop density, crop uniformity with alteration in row spacing had powerful and constant depressing outcomes on weed biomass and affirmative outcomes on biomass and yield of the crop. Competing varieties might be more efficient in the reduction of the capability of weeds throughout competitiveness for restricted sources. Finally, nutrient balance is frequently essential for crop-weed competition, and controlling the fertilizer applications in space and time might be a technique for useful weed suppression. Hence, the manipulation of certain agronomic integrated with competitive cultivar is a promising way to reduce weed interference in crops and to improve the sustainability of cropping systems through less reliance on herbicides.
  • Kirje
    Optimization of options for differential application of nitrogen fertilizers in the precision farming system
    (Estonian Academic Agricultural Society, 2020) Мatvejenko, Dmitriy; Komarov, Аndrei; Nugis, Edvin; Lekomtsev, Peter
    This paper aims to present the use of various treatments for the differential application of nitrogen in the precision farming system. To assess the state of the vegetation cover, both ground-based observations and associated remote sensing methods were used. Assessment of the state of plants (Menkovsky of AFI, 2009–2011) was carried out according to the phases of their growth and development using an N-tester in the field, as well as analysis of plant samples in a specialized laboratory. Remote sensing was carried out at the time of the analysis of plant samples using unmanned aerial vehicles equipped with cameras that allow shooting in different areas of the spectrum. The test sites with predetermined doses of nitrogen fertilizers for decrypt the obtained images were used. It is shown that for differential application of nitrogen fertilizers in spring wheat crops it is advisable to use the optical characteristics of the state of plants performed using calibration test sites. We have found that the maximum yield in the differentiated nitrogen applications treatment (TK-4) was 4510 kg per hectare (kg ha–1 ). At the same time, the minimum in the TK1 treatment was 3780 kg ha–1 . On average, over the years of research differentiated fertilizer application increased the collection of protein per hectare by 15–17%. In the TK-4 treatment for three years, a grain was obtained that corresponded to the first quality class (exceed 14%) in terms of protein content. Our novel research has shown that for characterizing the state of plants an assessment is given which was performed using calibration test sites.
  • Kirje
    Siseõhu kvaliteet põhu- ja pilliroopakkidest seintega elumajades
    (Estonian Academic Agricultural Society, 2020) Raamets, Jane; Ruus, Aime; Ivask, Mari; Nei, Lembit; Muoni, Karin
    Straw and reed are natural local insulation- and construction materials, which properties allow them to replace energy intensive building materials. In general, straw and reed as building materials are considered harmless to the environment and human health. Unfortunately, the use of these materials may bring about mould growth in buildings which may result in different diseases (for example irritation of eyes, nose and throat, allergic rhinitis, conjunctivitis, and asthma) in people with weaker immune systems. No research has been carried out on the topic of microbiological community in straw and reed houses in climatic conditions similar to Estonia, although buildings made of natural materials are becoming more and more popular. The aims of the study were to investigate the indoor climate of buildings with straw and reedbale walls and to determine the factors influencing indoor air quality. In order to fulfil the set aim: (1) air quality was tested in the bedrooms of the studied houses, and the microbial species in air and walls were determined; (2) the indoor air quality parameters (CO2, RH%, and temperature) in air and at two different heights in the walls were measured. The results enable to conclude that the walls of straw or reed-bale house are suitable in Estonian climatic conditions, which as a result of professional design, usage of materials suitable for building, and high-quality craftsmanship provides a healthy and environmentally friendly housing.
  • Kirje
    Express-diagnostics method for assessment of soil compaction for different cultivation methods
    (Estonian Academic Agricultural Society, 2020) Nugis, Edvin; Tamm, Kalvi; Võsa, Taavi; Plakk, Tiit; Palge, Veli; Estonian University of Life Sciences. Institute of Technology
    Soil compaction remains a concern because of the heavy tractors used in intensive agriculture. When axle loads of vehicles increase, soil compaction is affected in deeper soil layers. An efficient tool is needed to assess the impact of machines on soil. Therefore, an expressdiagnostics method was developed and implemented under Estonian agricultural conditions. Since 1976, an investigation has been carried out on how wheeled or tracked vehicles (WTV) influence soil under agricultural conditions in Estonia. The main goal of the investigation was to develop a mathematical model and corresponding computer simulation system. Uncompacted and compacted soil was modelled using a vegetation model of "guttated vegetation miniatures". The system allows soil vulnerability to compaction to be assessed by the criterion (qabc) agroempirical bearing capacity (ABC). Both field and laboratory data were used in the development of the system. We have found that at the deepest layer the bulk density was higher for tilled soil compared to no-tilled soil. Dry soil bulk density in no-tilled soil after 2 years in the deepest layer was 0.11 Mg m3 –1 less than tilled soil, and for no-tilled soil after 3 years in the deepest layer it was 0.12 Mg m3 –1 less compared to the tilled field soil. The amount of agronomically preferable aggregates (2–4.75mm) was major in tilled soil compared to no-tilled soil. It means that the preferred (in agronomical sense) soil particles Kstr in conventionally tilled (ploughing – K2; K3) fields were significantly better compared to no-tilled (O2; O3) fields in the trial plots. These results emphasize the benefits of multifunctional modelling systems (computer simulation and simulation by vegetation miniatures) and the need to improve assessment of methodology for receiving adequate and probable results, and finally for yield prediction.
  • Kirje
    A study of the interaction between soil and the pneumatic wheels of agricultural gantry systems
    (Estonian Academic Agricultural Society, 2020) Bulgakov, Volodymyr; Olt, Jüri; Kuvachov, Volodymyr; Chernovol, Mykhailo; Sviren, Mykola; Kolomiiets, Serhii; Estonian University of Life Sciences. Institute of Technology
    At the stage at which agricultural gantry systems are being designed, developed, and studied, the question of a rational choice of tyres for such systems is relevant, as tyres are the most important part of an agricultural gantry system and have a significant effect on most of its operating properties. The methods that can be used for choosing tyres for traditional mobile-powered equipment are already well established by scientific experience, but the movement of agricultural gantry systems in permanent artificial tracks creates somewhat different conditions and demands for a pneumatic tyre when compared to a traditional tractor moving along agricultural soil. This is why the development of methods that will assist in finding rational parameters for the pneumatic tyres of agricultural gantry systems that are moving along compacted soil in permanent artificial tracks is an urgent and relevant task. The purpose of the study is to optimise the parameters for the tyres of agricultural gantry systems in terms of their being able to travel on compacted soil in permanent artificial tracks. Theoretical studies and the synthesis of the parameters for a pneumatic wheel to work with an agricultural gantry system took place by modelling on a PC the performance conditions of such a vehicle. The basis for the study methods was formed by the fundamentals of tractor theory and theoretical mechanics, using the software program Mathcad. The traction factor of an agricultural gantry system's pneumatic wheel was used as the performance criterion for the effectiveness of the work being done by the wheel. The physical object of study was an agricultural system that has been developed by us. As a result of the study, it was determined that the solving of the task that has been set out - using an analysis of partial derivates of the function of the efficiency of an agricultural gantry system's wheel – makes it possible to quickly and effectively determine the rational optimum points for its pneumatic tyre's parameters. It was determined that, for the agricultural gantry system at hand, and in view of the maximum efficiency of its pneumatic wheel, the wheel's tyre width must be within the range of 0.20–0.30 m and its diameter must be within the range of 0.90–1.25 m. With those ranges, it is recommended that the tyre's inflation pressure be increased from 100 kPa to 160 kPa because the partial derivates of the function of the efficiency at those parameters would decrease to near zero. It has been proven that the choice of tyre type for agricultural gantry systems should be based first on the choice of its width and then its load-bearing capacity – its diameter. The proposed methods for finding rational parameters for pneumatic wheels make it possible to determine the tyre parameters for all kinds of agricultural gantry systems which will be required to travel on compacted soil in permanent artificial tracks. For the agricultural gantry system that has been developed by us, using tyres of the 9.5R32 type provides the highest levels of efficiency, i.e. at a factor of 0.86.
  • Kirje
    Ülevaade: Ravimijäägid reoveesettes ja nende lagunemine kompostimisel – viimase aastakümne uuringud Eestis
    (Estonian Academic Agricultural Society, 2020) Nei, Lembit; Haiba, Egge; Lillenberg, Merike; Eesti Maaülikool. Veterinaarmeditsiini ja loomakasvatuse instituut. Toiduhügieeni ja rahvatervise õppetool
    Pharmaceuticals are present in sewage sludge and its compost. This may cause severe health problems due to the plant uptake of pharmaceuticals by food plants when sewage sludge compost is used for fertilizing agricultural soils. Recently studies were conducted for estimating the efficiency of composting technologies in the view of the degradation of pharmaceutical residues. Experiments on plant uptake of pharmaceutical residues showed, that this phenomenon could not be ignored when using sewage sludge compost as a fertilizer. Novel approaches were developed via optimising the composition of the compost mixture with the aim of utilising sewage sludge compost as a nutrient-rich source for the improvement of soil properties. Sawdust as a bulking agent clearly speeded up the degradation of most of the studied pharmaceutical residues present in sewage sludge and its compost. More work in this field is needed for increasing the efficiency of the sewage sludge composting process. Efficient express methodologies should be developed with the aim of assessing the safety of sewage sludge compost.
  • Kirje
    Lühiartikkel: Eesti ajalooliste mõisaparkide ja metsade puistu liigilise koosseisu võrdluse meetod
    (Estonian Academic Agricultural Society, 2020) Nutt, Nele; Kubjas, Ardo; Kaplinski-Sauk, Minea
    The following short communication article presents a method for comparing the species composition of Estonian forests and parks, giving an overview of the data that is currently being gathered and underlining how these two datasets can be compared. Even though both forest and park inventories are carried out throughout the country, to this day there have been no comparative studies on how the species composition of parks and forests differ from each other. This stems from the fact that the park and forest inventories are carried out using different methods. Forest inventories classify most of the trees according to their genera, but also differentiate between the species composition of the forest canopy and sub-canopy layers. The park inventories classify all dendrological plants by their species, also measuring several other individual parameters. The main difference being that park inventories do not differentiate between different canopy layers, rather providing species composition charts that include all the dendrological plants growing in the park. In order to compare the two datasets, it is necessary to transfer the data derived from manor park inventories to match that of the Estonian forest inventory. The first step in implementing the method is to divide the inventory data from parks into the forest canopy and sub-canopy layers. The canopy layer of parks was determined to consist of old trees (>100 years). The age of the trees in parks was modelled after growth charts compiled from the data from Estonian forests, which was then extrapolated to reach 120 years. These growth charts were compared to the breast height diameter of park trees, to determine their age. The canopy layer of parks was then analysed to provide an overview of species composition that corresponds to the same level of generalisation as the forest inventories. The results showed that the species composition of old manor parks differs significantly from most Estonian forests with the majority of the trees in parks being broad-leaved. The proposed method is suitable for comparing forests and parks on a generalised level.